Connectors of this kind are known and used on an automotive steering wheel as shown in FIG. 5 and in other applications. Referring to FIG. 5, a movable body 1 has a cylindrical portion 1a of a reduced diameter, and a steering wheel (not shown) is firmly fixed to the body 1. A stationary body 2 rotatably holds the movable body 1. In this assembled state, a given space is defined between the outer periphery of the cylindrical portion 1a and the inner surface of the stationary body 2 in which the cylindrical portion 1a is inserted. Several turns of a belt-like flat cable 3 are received in this space. The inner end of the cable 3 is attached to the movable body 1, while the outer end is fixed to the stationary body 2. When the movable body 1 rotates, the cable 3 is wound or unwound according to the direction of the rotation. Thus, the diameter of the cable varies. The cable 3 is fabricated by inserting a plurality of conductive sheets made of copper or other highly conductive material between two base sheets of a flexible film as made from polyester. Electric signals are transmitted between the movable body 1 and the stationary body 2. For example, a signal indicating an automobile horn is fed from the movable body, or steering wheel, to the stationary body.
Electrical devices which have been practically mounted on the steering wheel are not restricted to an automobile horn as mentioned above. For instance, light switches and various other devices are installed on it. Where several kinds of electrical devices are mounted on the movable steering wheel, especially when it is necessary to install a number of input keys of an automobile telephone, for example, on the steering wheel, the number of the signal lines is very large accordingly. In the conventional structure where one flat cable is wound as described above, the cable is very wide. This makes it difficult to install it on the steering wheel which has a limited width.
Also, where several kinds of electrical devices are installed on the steering wheel, the electric currents consumed by these devices are not always of the same order. Sometimes, relatively large electric currents must be supplied to some conductive sheets of the cable, whereas minute currents must be fed to other conductive sheets. In this case, with the conventional structure making use of the conductive sheets of the single flat cable to supply electric currents, all the circuits are required to use an expensive flat cable, based on the circuit consuming a large amount of current. As an example, such an expensive cable consists of a wide plate of copper coated with heat-resistant base film as made from polyimide. Hence, it has been difficult to fabricate the conventional structure economically.
Further, in the conventional flat cable used in the connector device, relatively soft conductive sheets as made of copper are held between base sheets of film. Therefore, the resistance of the cable to flexure is not sufficiently high. Thus, when the movable body rotates and the diameter of the cable varies as mentioned above, there is the possibility that the cable is bent at a location, causing the corresponding conductive sheets to break. Especially, when the number of turns of the cable is reduced and the cable is shortened, a larger friction takes place between neighboring turns of the cable. Consequently, the aforementioned tendency becomes more conspicuous.